CN1142679C - Color scanner using both varible led exposure time and photodetector output compensation - Google Patents
Color scanner using both varible led exposure time and photodetector output compensation Download PDFInfo
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- CN1142679C CN1142679C CNB961965495A CN96196549A CN1142679C CN 1142679 C CN1142679 C CN 1142679C CN B961965495 A CNB961965495 A CN B961965495A CN 96196549 A CN96196549 A CN 96196549A CN 1142679 C CN1142679 C CN 1142679C
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/46—Measurement of colour; Colour measuring devices, e.g. colorimeters
- G01J3/50—Measurement of colour; Colour measuring devices, e.g. colorimeters using electric radiation detectors
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/02—Details
- G01J3/027—Control of working procedures of a spectrometer; Failure detection; Bandwidth calculation
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/46—Measurement of colour; Colour measuring devices, e.g. colorimeters
- G01J3/50—Measurement of colour; Colour measuring devices, e.g. colorimeters using electric radiation detectors
- G01J3/501—Colorimeters using spectrally-selective light sources, e.g. LEDs
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
- G01J3/46—Measurement of colour; Colour measuring devices, e.g. colorimeters
- G01J3/52—Measurement of colour; Colour measuring devices, e.g. colorimeters using colour charts
- G01J3/524—Calibration of colorimeters
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/40—Picture signal circuits
- H04N1/40056—Circuits for driving or energising particular reading heads or original illumination means
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- H—ELECTRICITY
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- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/40—Picture signal circuits
- H04N1/401—Compensating positionally unequal response of the pick-up or reproducing head
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- H—ELECTRICITY
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- General Physics & Mathematics (AREA)
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Abstract
The present invention provides a combination of first providing a coarse adjustment by varying the emitter (1-1 to 1-n) power and duration of the emitter/detector exposure time (SL-1 to SL-n), and then providing a fine adjustment by storing (13) a correction value for each photodetector element (5). The adjustement for each photodetector corrects not only for the range, but also for the offset, providing two correction values. In a preferred embodiment, the low (offset) and high (offset plus range) voltage reference levels for an analog to digital converter (8) are adjusted and stored for each photodector for each color.
Description
Technical field
The present invention relates to the Color image scanner and its operation method such as image analyzer, facsimile machine and photocopier, particularly to the optical transmitting set output flow of variation and the Color image scanner and its operation method of transducer sensitivity compensation.
Background technology
The existing multiple device that is used for the sensing coloured image.These devices can be desk-top or handheld scanner, photocopier, facsimile machine or other device.They adopt multiple distinct methods.In one approach, use the fluorescent lamp image, different colour filters are set in case before transmitted light or reverberation are sensed with its blocking.As an alternative, can use a plurality of fluorescent lamps, each light fixture has the colour filter that is used to launch different colours light of himself special use.In other device, adopt light-emitting diode (LED) to replace fluorescent lamp, different LED has the different color emission.For example, a kind of typical structure can have three kinds of LED, and is a kind of at blue wavelength region, another kind of in the green wavelength scope, and a kind of at red wavelength range.
Adopt the problem of LED to be: for the light emitted radiant flux of the different LED of same color, or even light emitted mean wavelength changes between LED and LED with manufacturing process.Because the combination of the value that the particular color of image is three kinds of different colours from reflection to be received reconstitutes, for example, if change in the different directions between green and blue led, these variations can not only produce error, and error is amplified.Another problem of this device is: light-sensitive device itself has different sensitivity according to the light wavelength that is received.Therefore, for two kinds of catoptrical identical radiant fluxes of different colours, light-sensitive device can provide the discrepant output of value of the image surveyed of expression, and therefore causes that the color at the image that is detected has error.
Fig. 4 illustrates this effect of three kinds of dissimilar LED.Fig. 4 is along the wavelength of trunnion axis with along the curve chart of the relative spectral response of vertical axis.The transducer sensitivity of solid line 28 expression photoelectric devices.As can be seen, sensitivity has lower sensitivity with wavelength change at short wavelength.What superposeed is the graphic extension of the Wavelength distribution of the LED that indicates of three kinds of particular colors, and any independent LED will launch the light of many different wave lengths, and its radiant flux is consistent with indicated distribution haply.Owing to can use photoresponse function 26 to calculate, first kind of LED20 (blueness) has a kind of relative spectral power and distributes, wherein for the identical accumulative total luminous flux that provides during the relative spectral power of second kind of LED22 (green) distributes, light-sensitive device will provide the output of three times the first kind that is roughly second type.Equally, the third LED24 (redness) has a kind of relative spectral power and distributes, wherein for the identical accumulative total luminous flux that provides during the relative spectral power of second kind of LED22 (green) distributes, light-sensitive device will provide the output of 12 times the 3rd type that is roughly second type.
Another kind of effect has been described among Fig. 5, has wherein shown luminous flux output as the function of the electrical power of three kinds of different LED.Being designated as first kind of LED1-1 (blueness) of 20 has than other two kinds of output light fluxs that LED is much lower.Being designated as 22 LED1-2 (green) has and is designated as 24 LED1-3 (red/orange) light output flow much at one.Therefore, except that the light-sensitive device with different spectral responses, the output of LED itself will change at the equal-wattage amount that is applied to LED.
Basically there are two kinds of recognition results above the method compensation.For example in disclosed first method in the U.S. Patent No. 4,731,661 of Sharp company, realize compensation by the time quantum that changes different optical transmitting set conductings.In the patent of Sharp company, three kinds of different fluorescent tubes are used for three kinds of different colors, change the spectral response of the time quantum of each fluorescent tube conducting with the variation of compensation light-sensitive device.Normally used light-sensitive device is by responding the light of sensing as the output voltage of the integral function that receives light.Therefore, the logical time of photoconduction is long more, and the output of light-sensitive device is high more.So, light-sensitive device is had the sensitivity that compensate for slower is low of longer ON time to its not too sensitive wavelength.
In U.S. Patent No. 5,268, another example how to compensate is disclosed in 752.In this patent, use the LED of different colours.For each LED, with the output of compensator circuit compensation detector.
U.S. Patent No. 4,833,533 outputs that how to disclose in more detail light-sensitive device compensate.At No.4, in 833,533 patents, read 7 sample strip, for each pixel of every kind of color is deposited value of arm with a transducer.In other words, compensation is applied to a pixel, and compensation is applied to a kind of color by each color of pixel base by the pixel base.This offset is stored in the memory, calculates the compensation ratio that is applied when reading an image with scanner then.
Summary of the invention
The invention provides a kind of power and duration of reflector/detector time for exposure that at first offers reflector by change provides coarse adjustment, then by storing the combination that a corrected value provides thin tuning for each photodetector components.The adjusting of each photodetector is correcting range not only, and proofreaies and correct skew, and two corrected values are provided.In a preferred embodiment, according to the low and high voltage reference level of not regulating A/D converter for the value of each photodetector storage, to produce the numeral output of proofreading and correct at every kind of color.
In a preferred embodiment, the LED power by employingization and provide time for exposure of coarse adjustment to scan a pair of test-strips to realize regulating.A test-strips is light grey, and another test-strips is a Dark grey.Determine the value of these samples then, and calculate skew and scope correction.The correction of being calculated is corresponding to the extrapolation in the white of scope end and black value, but does not measure by this way, avoiding the slicing effect in the scope end, and applies with the numeral that obtains to proofread and correct as suitable benchmark and to export.
In another scheme of the present invention, LED arranges by interlace mode, and multiple color comes same delegation.Change regularly the length of blue led ON time ratio green and red LED, the time cycle that green that ON time is identical and red LED conducting are short by the ON time that changes LED.But come the select time cycle by the minimum time amount of determining green and red LED conducting, and still mate, when blue led conducting amount of available maximum time reaches maximum power to realize required sweep speed with the output of blue light sensing device.
Description of drawings
Characteristic for a more complete understanding of the present invention and advantage, should be in conjunction with the accompanying drawings as reference to subsequently detailed description.
Fig. 1 is the block diagram of the electronic circuit of scanner according to the present invention;
Fig. 2 A and 2B have illustrated several possible arrangement of optical element of the present invention;
Fig. 3 is the schematic diagram according to LED distribution embodiment of the present invention;
Fig. 4 is the curve chart of sensor light spectral sensitivity, photoresponse function and the relative spectral power of sampling LED;
Fig. 5 is the curve chart of the luminous flux of different PED;
Fig. 6 A and 6B are the schematic diagrames of the photoconductive tube that uses in one embodiment of the invention;
Fig. 7 is the schematic diagram of light-sensitive device circuit different elements;
Fig. 8 is the timing diagram that changes the ON time of LED according to the present invention:
Fig. 9 is the explanation schematic diagram of the content of calibration storage; With
Figure 10 is that explanation A/D reference voltage is regulated the curve chart that calculates.
Embodiment
Fig. 1 is the system schematic of one embodiment of the invention.A plurality of led array (1-1 to 1-n among Fig. 1) are launched the light of different spectrum and are driven by a led drive circuit 9.Come exposure chart that for example the surface of the visible object 3 of original copy, chart, figure, photo and so on (hereinafter being referred to as body surface) is shown with the light of launching from led array with linear mode basically.Before light shines body surface by an optional transparent window 16, can make from the light of led array emission by an optional optical element 2 (hereinafter being referred to as photoconductive tube) to change direction and/or convergence and/or homogenizing.Passing the linear array that transparent element (if any) enters light-sensitive element 5 afterwards once more from the light of this body surface reflection, and be shown in as Fig. 2 A pass a selfoc lens array 4 (hereinafter being referred to as S.L.A) under the situation of normal contact-type imageing sensor after, or need not to pass the linear array that a S.L.A enters light-sensitive element 5 under the situation as Fig. 2 complete contact-type image sensor that B is shown in.Led array can all be provided with in a side setting of sensor array or in both sides as shown in Figure 2.
Timing generator 12 provides all operations synchronous usefulness of fundamental clock frequency (fo) for this device to ASIC14.Led drive circuit 9 responses provide suitable power level from the timing signal (SL-1 to SL-n) of ASIC14 to led array (1-1 to 1-n).Descending for each of file, each led array 1-1 to 1-n before moving on to next line by sequence starting.Start a kind of whole array of particular color simultaneously, rather than with its single startup so that produce delegation's light.Though in Fig. 1, illustrate, as following another embodiment possibility of discussing with respect to Fig. 3 better with linear array.
Motor-drive circuit 10 produces the required enabling signal of motor 6, so that the sub-scanning of original copy 3 is finished in response from the motor drive signal (SM) of ASIC14.With regard to motor, though also can adopt can discontinuous fluid linear stepping type or other type, adopt rotation stepper type the most favourable.Motor or the inswept paper of motion scan device, or make the inswept scanner of paper.Once move and move a step or delegation each led array of startup before next time moving.
Sensor drive driving circuit 11 will convert the required pulse of sensor array 5 from the timing signal (SI and CLK) of ASIC14 to, to finish the main scanning operation.Particularly, to coming from the data timing of light-sensitive device,, these data are moved out to amplifier 7 like this if use the output of shift register.The amplifier 7 always output voltage of autobiography sensor array (SO) applies consistent bias voltage (optional is zero) and consistent gain coefficient (optional odd or even number is non-linear), so that they are included in the scope of mould/number (A/D) transducer 8.The output of A/D converter 8 is offered ASIC14, it can be stored in the memory or provide via the output port of scanner at this.The correction coefficient of memory 13 storage light-sensitive devices, in the preferred embodiment that is discussed below, these apply by a reference drive 17, so that set low (skew) and high (skew adds scope) voltage reference value of A/D converter 8 for each specific light sensing device pixel of every kind of color.
ASIC14 by 12 couples of Fig. 1 of timing generator carries out synchronously, so that access memory 13 and removing at further image processing, show, print, modulator-demodulator transmit or any purpose of facsimile transmission through port one 5 to master computer transmit control and data signal outside, also to all drive circuits (9,10,11, with 17) signal is provided, can resemble this device of control to obtain gray scale or binary picture representation and/or the alternately operation of this class of dateout representation (for example data formatting and/or data compression/coding and/or color space conversion) is provided so that carry out in one way to the ASIC allocating task in addition.
Shown in Fig. 2 A, arrange at led array and photosensor array 5 angles at 45, LED can have in one or both sides, in arranged on both sides light intensity will be doubled, its cost is to increase optional feature, 90 ° of angles of adopting 45 rather than directly reflection are so that provide stronger diffuse reflection, and this is particular importance when reading big machine-glazed paper.Shown in Fig. 2 B, can remove the SLA4 among Fig. 2 A in one embodiment.
Fig. 3 illustrates the example that led array is arranged and made up.This example proves that certain line is not essential, and the quantity of LED type also is not limited to a kind of in the array.Yet, under the simplest situation, minimumly arrange three kinds of LED linearly, so that array is staggered with figure neat and intensive repetition roughly.Allow so very these arrays to be set near body surface, so as can do not use photoconductive tube 2 or use photoconductive tube with reduce cost and the situation of complexity under, from each array irradiating object surface fully and more equably.
As shown in Figure 3, four kinds of different colors are staggered, and these color showings are 1-1,1-2a, 1-2b and 1-3.Another program, can with one of position for example 1-2b keep need not, in every group of tube core three LED are arranged like this, be arranged in L shapedly, the common connection finishes that this is square.In another embodiment, compare with other LED, double and can carry out addressing to the luminous flux of the blue led that reduces by the amount that makes blue led, therefore, for example, the LED position of 1-2a and 1-2b can all be a blue led among Fig. 3.
Fig. 6 A and 6B illustrate an example of photoconductive tube 2, its objective is in that luminous quantity is changed hour, compile light from this array at auxiliary scanning direction (vertical) with this line sensor in the sensor array.This device has reduced required LED quantity, provides enough illumination to body surface 3, proves that it can reduce cost.As what seen in Fig. 6 A, photoconductive tube is positioned on a plurality of LED position 30.The middle body 32 of photoconductive tube has a diffuse scattering surface that is used to spread from the light of LED.
Fig. 6 B illustrates the sectional view of the photoconductive tube 2 of Fig. 6 A.Light from LED30 passes diffuse scattering surface 32.The oval surface 34 of a mirror-polishing is set in photoconductive tube top and bottom.A side 36 far away is transparent surfaces, and light passes this surface irradiation to the body surface that is scanning.In Fig. 6 B, should note.With an angle body surface is shown, so that observe photoconductive tube by the light path horizontal line.The auxiliary scanning direction that arrow 38 expression scanners move.As can be seen, light passes and was scattered in surperficial 32 o'clock, to spread the too wide any light of angle and be reflected by surface 34, photoconductive tube makes from being evenly distributed of the light of the LED that separates so that to the exposure intensity of those parts between the LED more near those parts that directly are in below the LED.Remaining compensation rate is undertaken by the correction when a test-strips is read in the light-sensitive device conducting as described below.
Fig. 7 illustrates the functional-block diagram of sensor array 5.The linear array (5-1) of this sensor array comprises a plurality of (quantity is m) light-sensitive element, correspond respectively to the memory element (5-3) of array, make the response of any conversion of sensing be sent to the device (5-2) of its corresponding memory element and sequentially read independent response (any conversion) conduct that keeps in each memory element and the device (5-4) that adds up the voltage of incident illumination functional dependence simultaneously from all light-sensitive elements.In the operation, input signal SI starting drive 5-2 is to be accomplished to the transmission of memory element, and input signal CLK starting drive 5-4 is to finish reading as proficiency row output voltage SO memory element.In an example, device 5-4 is one and is continuously removed shift register from the parallel input of memory element 5-3 to output SO.
Fig. 8 is a timing diagram, and it shows by ASIC (14 among Fig. 1) according to the universal relation between some signal of some (T) generations in the fundamental clock frequency (fo) that is provided by timing generator (12 among Fig. 1).These signals are SL-1, SL-2 and SL-3 of led drive circuit (9 among Fig. 1); The SM of motor-drive circuit (10 among Fig. 1); And the SI and the CLK of sensor drive driving circuit (11 among Fig. 1).This illustrates the timing of three led array, is simple yet expand to wider.The sensing duration that it also shows two color components equals to be used to read the situation of required duration, though this is not necessary.The part timing of dotted line 40 belows among Fig. 8 (first row of body surface is read in expression incessantly) is extended (expression only surpasses the duration that a kind of color component reads slightly) on dotted line.
Between each process (SM) of motor, each (SL-3, SL-2, SL-1) of three led array of irradiation.After shining first led array (SL-3), signal SI makes its sense data, simultaneously a kind of color under the sensing.A series of read values of all light-sensitive devices of the SO signal indication SL-3 color above the dotted line 40.Because this reads the minimum time amount of needs, this is the minimum time of led array conducting.The led array that ON time is long (promptly blue) prolongs signal SI.A kind of result finishes reading preceding a kind of color before next SI signal.For this is calculated, from the SO signal virtual counting (X) that successively decreases, to form this difference.
Come with reference to figure 5, the present invention makes the light-sensitive device output of three kinds of LED and the combinations matches of light-sensitive device again.This is to be roughly (1/12) than 1 than (1/3) by the ratio that requires red with green with blue accumulative total luminous flux under the identical time for exposure, or in the time for exposure of blueness be under the situation of red and green twice its ratio for (1/12) than 1 than (1/6) realization.This can realize by the power that 2.5mW, 1025mW and 250mW are provided respectively to red, green and blue type LED, cause output light flux to be respectively 0.75mlm, 9mlm and 1.5mlm.Therefore, the power that offers blue LED surpasses 10 times of power of red LED, is preferably 100 times of this power in the example that provides.As appreciable, the power that offers red LED only is enough to it is started, and the power that offers blue LED only is lower than its heap(ed) capacity.Avoided like this requiring using different amplifier gains realizing this coupling, but allow may be to the use of this different amplifier gains for every kind of color, thereby with the visual sensitivity of the relative noise level explanation people between the control color.
For example, people compare the low of green glow high noise level to the dislike degree of the high noise level of blue light.The power that offers blue LED is 50% of maximum DC rated value at least, more preferably greater than the DC rated value, but is no more than the maximum impulse frequency of the duty cycle of use.Because programming does not stop it under the situation of LED conducting to scanner, so can use this higher level.Using different timing in the present invention rather than using an advantage of different magnification ratios is to have improved signal to noise ratio, all the more so to blue light especially.
Fig. 9 illustrative ground (rather than using literal) has illustrated the formation of the memory 13 of Fig. 1.Yet this memory can be DKAM, VRAM or often do not write can be fast and other type of repeated access.On behalf of which A/D reference voltage, " j ", direction " i " represent which position of components and " k " to represent which kind of color component.In the calibration storage is digital code value, by ASIC14 along the circulation of " i " direction and access sequentially these, therein along circulation of " j " direction and sequential access, therein along circulation of " k " direction and sequential access.Intermediate storage of data and/or data output that other memory location can be used for being compensated cushion.Then, ASIC provides two digital codes to the reference driver circuit 17 of Fig. 1, a low reference voltage (Vref-) that is used to regulate A/D, a high reference voltage (Vref+) that is used to regulate A/D.In fact two of " i " direction can reside in the memory 13 as unique one, and ASIC14 analyzes it before this is presented to reference driver circuit 17.Can regard the reference driver circuit 17 of Fig. 1 as two D/As (D/A) aptly, may be actual yet make two resistance-resistor networks.
Item in the calibration storage will be stored after determining with it during the initialization process that may only occur once or occur once in a while.This initialization need read two unanimities, non-selected, the neutral gray target of spectrum, one is the Dark grey shade D of reflectivity, another is the light grey shade L of reflectivity, these two targets are that calibration storage is at first set, so that the Vre-that will use and the maximum magnitude between the Vref+ to be provided.Each shade is read multirow and to its equalization, with the mean value (R of each shade of each element of obtaining every kind of color component of representative
dAnd R
l).As what in the curve of Figure 10, describe, in definite process of calibration storage item, use the extrapolation of the mean value (α and β) of these measurements, this figure has only considered a kind of color component of an element.For clarity sake, between Figure 10 hypothetical target reflectivity and the device response be linear relationship, and in final data respectively as lowest numeric output valve MIN and maximum number output valve MAX represent from black B to the desirable reflectivity range of white W (respectively from zero hundred different to nasolabial groove).The target of the black and white value of unactual use and to adopt the reason of this extrapolation be to avoid calculating the influence of possible amplitude limit mean value because of required precision, item in the calibration storage should be the digital value that is encoded, and is used for drawing the low of desirable calibration from reference driver circuit 17 and (is respectively Vref-with high reference voltage
CalibratedAnd Vref+
Calibrated).
A/D converter can be usually alleged flash A/D type, but should have in any case be used for will be relevant the aanalogvoltage input be mapped to low reference level (Vref-) and the high reference level (Vref+) at digital output area two ends, these reference levels can be adjusted to respectively and allow the conversion generation Anywhere and still in a certain scope corresponding with this reference level.
The alternative embodiment of these embodiment that can provide.The functional-block diagram of Fig. 1 and not meaning that is meant the separating component (for example, amplifier 7 can be included in the identity element as sensor array 5) of these functions of expression.
In Fig. 2, if rotating around vertical axis, someone imagination carries out optical arrangement symmetrically, he will draw an alternative embodiment.Led array 1 and photoconductive tube 2 are annular, and available einzel lens substitutes S.L.A.4, and sensor array will be the area array in a limited visual field, rather than linear array.Two motors are arranged; A motor is used at the auxiliary scanning direction controlled motion, another motor is used for being controlled at the stepping of main scanning direction, these motors have the effect with respect to original copy mobile optical sensing subsystem, sensor array can be frame transmission type zone C CD, CMOS area sensor, or has other photosensitive region array of associated storage part.In this embodiment, master computer has these dizzy attachments of a task of reflecting the formation original image of combination, but ASIC14 can more effectively send data to master computer by data being carried out various two dimensional compaction (for example JPEG), and does not need too many memory.This regional scanner array can carry out the raster scan operation at a kind of color component.In others, this alternative embodiment and preferred embodiment are basic identical.
Discrete component is known the mutability of the sensitivity of light in the contact-type image sensor array, and has designed several schemes and improved this mutability.A kind of method is to allow for the cumulative time that each element changes light.This technology can not directly be applied at present this same; In time, appears at and is the situation of a kind of color component of all element sensings in the full line.
Another kind method proposes this problem by the proportional output valve from digitized input value and one compensation of recognition component index.This technology data area that remaps effectively, but continue to run into the problem of non-best initial quantization.The present invention is according to the A/D reference level of an element regulation (skew adds the high reference level of scope) through color component, so that compensate predetermined light output, light transmits, change with the interblock space of the sensitivity of the element that occupies each relevant position at every kind of color component, the present invention regulates another A/D reference level (the low reference level of skew), so that according to spatial variations through a predetermined dark response of element of color component compensation, the back is a kind of even the adjusting of the color component of identity element compensated dark response as (with in the color component of the present invention at least a different) function of corresponding cumulative time outwardly, though it also has favourable influence to sheltering other line time stationary noise source.This technology can more preferably quantize desirable signal.
Those skilled in the art should be appreciated that, can implement the present invention by other concrete form under the situation that does not break away from the present invention's spirit or its substantive characteristics.For example, can use the color of varying number or different led array to arrange.As an alternative, can change the ON time of light-sensitive device rather than the ON time of change LED.Every group of LED can comprise the LED of different colours, produces main one synthetic color (as long as three kinds of different synthetic colors are arranged).As an alternative, can adopt other method of proofreading and correct skew and gaining the two, rather than adopt the low and high reference voltage of the A/D converter of this instantiation.Therefore, the intention of open the preferred embodiments of the present invention is not restriction and be to illustrate the scope of stating in the following claim of the present invention.
Claims (19)
1. color image scanner comprises:
A light emitter arrays, at least three groups, every group of reflector with a plurality of at least a colors;
A plurality of photodetectors;
Conversion equipment is used for converting the sensing exposure of each described photodetector of each described optical transmitter bank to a digital value;
Timing device is used at least one at optical transmitter bank, starts the sensing exposure of whole described photodetectors to each described optical transmitter bank according to a kind of color or the multiple change color of reflector in every group;
Measurement mechanism is used for measuring the sensing exposure variations of each described photodetector of each described optical transmitter bank;
Memory is used for storing the indication of described variation of each described photodetector of each described optical transmitter bank;
It is characterized in that, also comprise:
Adjusting device, the power and the duration of reflector/detector time for exposure that offer reflector by change provide coarse adjustment, then by storing the combination that a corrected value provides thin tuning for each photodetector components, the adjusting of each photodetector is correcting range not only, and correction skew, two corrected values are provided, regulate the low and high voltage reference level of A/D converter for the value of each photodetector storage at every kind of color, to produce the numeral output of proofreading and correct, regulate the described device of each described photodetector of conversion with the described indication in the described memory, and change the time of described photodetector conducting;
Described timing device changes the time of described optical transmitting set conducting;
Conversion equipment is an A/D converter, and described indication comprises the high and low voltage benchmark of described A/D converter;
Described optical transmitting set has at least three kinds of different colors, and wherein said timing device starts the cycle very first time with the optical transmitting set of first kind of color, and with second and the optical transmitting set of the third color start the second shorter time cycle.
2. color image scanner according to claim 1 is characterized in that, the described cycle very first time is the twice of described second time cycle at least.
3. color image scanner according to claim 1 is characterized in that, each described reflector group is single a kind of color.
4. color image scanner according to claim 3 is characterized in that, also comprises electric supply installation, is used for changing the quantity of power that offers each described optical transmitter bank according to a kind of color of described optical transmitter bank.
5. color image scanner according to claim 4 is characterized in that, the quantity of power that offers first optical transmitter bank with minimal wave length be described first group described reflector maximum DC rated power at least 50%.
6. color image scanner according to claim 5, it is characterized in that, for given duty cycle, offer described first group quantity of power and be not more than its maximum impulse rated power greater than the maximum DC rated power of described first group described optical transmitting set.
7. color image scanner according to claim 6 is characterized in that, offers first group power with long wavelength and is lower than and offers 1/10 of second group power with minimal wave length.
8. color image scanner according to claim 1 is characterized in that, at least two described reflector groups are arranged in independent delegation.
9. color image scanner according to claim 1 is characterized in that, the quantity of power that offers first optical transmitter bank with minimal wave length be described first group described reflector maximum DC rated power at least 50%.
10. color image scanner according to claim 9, it is characterized in that, for given duty cycle, offer described first group quantity of power and be not more than its maximum impulse rated power greater than the maximum DC rated power of described first group described optical transmitting set.
11. color image scanner according to claim 10 is characterized in that, offers first group power with long wavelength and is lower than and offers 1/10 of with minimal wave length second group.
12. a method of operating color image scanner, described color image scanner are the described color image scanners of claim 1, described method comprises step:
Change the sensing step of exposure, comprising: convert the sensing exposure of each the described photodetector in each described optical transmitter bank to a digital value,
Start sequential at least one of optical transmitter bank, the color according to reflector in every group changes the sensing exposure of whole described photodetectors to each described optical transmitter bank,
Measure the sensing exposure variations of each the described photodetector in each described optical transmitter bank;
Change the time of described optical transmitting set conducting;
Change the time of described photodetector conducting;
Regulating step, pass through adjusting device, power and the duration of reflector/detector time for exposure that change offers reflector provide coarse adjustment, then by storing the combination that a corrected value provides thin tuning for each photodetector components, the adjusting of each photodetector is correcting range not only, and correction skew, two corrected values are provided, regulate the low and high voltage reference level of A/D converter for the value of each photodetector storage at every kind of color, to produce the numeral output of proofreading and correct, regulate the described device of each described photodetector of conversion with the described indication in the described memory;
Switch process uses an A/D converter, regulates the described device of each described photodetector of conversion with the described indication of the high and low voltage benchmark that comprises A/D converter;
Storing step, the variation indication of storing each described photodetector of each described optical transmitter bank.
13. method according to claim 12, wherein, described optical transmitting set has at least three kinds of different colors; The described step that changes the sensing exposure comprises: the optical transmitting set of first kind of color is started the cycle very first time, and with second and the optical transmitting set of the third color start the second shorter time cycle.
14. method according to claim 13, wherein, the described cycle very first time is the twice of described second time cycle at least.
15. method according to claim 12, wherein, each described reflector group is single a kind of color.
16. method according to claim 12 also comprises: the step that offers the quantity of power of each described optical transmitter bank according to a kind of color change of described optical transmitter bank.
17. method according to claim 16, wherein, the quantity of power that offers first optical transmitter bank with minimal wave length be described first group described reflector maximum DC rated power at least 50%.
18. method according to claim 17 wherein, for a given duty cycle, offers described first group quantity of power and is not more than its maximum impulse rated power greater than the maximum DC rated power of described first group described optical transmitting set.
19. method according to claim 16 wherein, offers first group power with long wavelength and is lower than and offers 1/10 of second group power with minimal wave length.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/497,459 | 1995-06-30 | ||
| US08/497,459 US5729361A (en) | 1995-06-30 | 1995-06-30 | Color scanner using both variable led exposure time and photo detector output compensation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1194076A CN1194076A (en) | 1998-09-23 |
| CN1142679C true CN1142679C (en) | 2004-03-17 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB961965495A Expired - Fee Related CN1142679C (en) | 1995-06-30 | 1996-06-21 | Color scanner using both varible led exposure time and photodetector output compensation |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US5729361A (en) |
| EP (1) | EP0835582A1 (en) |
| CN (1) | CN1142679C (en) |
| AU (1) | AU6390796A (en) |
| TW (1) | TW319938B (en) |
| WO (1) | WO1997002698A1 (en) |
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| US6201559B1 (en) * | 1996-12-19 | 2001-03-13 | Minolta Co., Ltd. | Method for measuring the quantity of light emergent from an optical tip array and image forming apparatus provided with an optical tip array |
| US6025589A (en) * | 1997-01-06 | 2000-02-15 | Texas Instruments Incorporated | Apparatus and method for normalizing multiple color signals |
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| US6205244B1 (en) * | 1998-06-23 | 2001-03-20 | Intel Corporation | Method for imager device color calibration utilizing light-emitting diodes or other spectral light sources |
| CN1069800C (en) * | 1998-07-03 | 2001-08-15 | 劳以迈 | Treatment of pseudo image element of LED color screen |
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1995
- 1995-06-30 US US08/497,459 patent/US5729361A/en not_active Expired - Lifetime
-
1996
- 1996-06-21 EP EP96923383A patent/EP0835582A1/en not_active Ceased
- 1996-06-21 AU AU63907/96A patent/AU6390796A/en not_active Abandoned
- 1996-06-21 WO PCT/US1996/010706 patent/WO1997002698A1/en not_active Application Discontinuation
- 1996-06-21 CN CNB961965495A patent/CN1142679C/en not_active Expired - Fee Related
- 1996-08-26 TW TW085110368A patent/TW319938B/zh not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| WO1997002698A1 (en) | 1997-01-23 |
| US5729361A (en) | 1998-03-17 |
| EP0835582A1 (en) | 1998-04-15 |
| TW319938B (en) | 1997-11-11 |
| CN1194076A (en) | 1998-09-23 |
| EP0835582A4 (en) | 1998-05-20 |
| AU6390796A (en) | 1997-02-05 |
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Assignee: Xuli Electronics (Guangzhou) Co., Ltd. Assignor: Lite-On Technology Corporation Contract fulfillment period: 2007.1.23 to 2021.12.5 contract change Contract record no.: 2009990000665 Denomination of invention: Color scanner using both varible led exposure time and photodetector output compensation Granted publication date: 20040317 License type: Exclusive license Record date: 2009.6.17 |
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